“I was out running with friends along the coastal path and we saw it in the water.

“My friend asked if it was a dolphin but it was far too big. It was difficult to figure out exactly what type of whale it was, but it banked up and came out of the water and we stood and watched it. There were bird watchers in a boat and they stopped to watch it too.

“I’ve always been interested in the sea, but it’s funny because people go to places like Canada to whale watch and we get to see them on our coast. It was very unexpected but very interesting.

“I felt like a school child watching it,” she said.

She added that when she went home no one believed her sighting: “We’ve had mice in our house, and no one believed me about the amount of them we had.

“No one believed us about the whale – I told my family and friends and they thought I was seeing things though quite a few of my friends saw it too and a few people have contacted me about it over Facebook,” she added.

The whale sighting is only the third validated sighting of a humpback whale in Northern Irish waters since records began.

A spokesperson from the Irish Whale and Dolphin Group (IDGW) said: “One concern we'd have is their habit of remaining close inshore, which raises a safety concern as there is always a risk of entanglement in fishing gear.

“Images from the coastal path show the whale swimming among such obstacles.

“We'd also point out that they are favourites among whale watchers due to their gregarious and inquisitive nature and this too can get them into trouble if boats insist in crowding them out.

“So, like every wild mammal, they need their space and we'd ask boat owners to maintain at least 100m distance between you and the whale; for your safety as well as theirs.”

The sighting of the humpback came in the same week as the protest by Northern Irish school children at Stormont for laws to protect our coastline.

Northern Ireland is currently the only part of the UK without legal safeguards for its coast and environmentalists have long been critical of the lack of statutory protection available for marine habitat areas off our shores.

The campaign to have the Marine Bill introduced is headed by the Northern Ireland Marine Task Force which represents eight different wildlife protection groups.